Making slide fasteners



May 10, 1938. G. SUNDBACK 2,116,547

MAKING SLIDE FASTENERS Original Filed Sept. 10, 1952 2 Sheets-Sheet 1 N VEN TOR Gideon gundbach' 21 BY fl S- ATTORNEY May 10, 1938. G SUND ACK 2,116,547

MAKING SLIDE FASTENERS Original Filed Sept. 10, 1932 2 Sheets-Sheet 2 Fig. 6. J4 J4 em 7I 61 I n n I l A TTORNEYS.

Patented May 10, 1938 UNITED STATES MAKING SLIDE FASTENERS Gideon Sundback, Meadville, Pa., assignor to Talon, Inc., Meadville, Pa., a corporation of Pennsylvania Application September 10, 1932, Serial No. 632,493 Renewed August 12, 1937 6 Claims.

This invention relates to slide fasteners of the type in which each of a. pair of flexible stringers, such as fabric tape, is provided along one edge with a series of interlocking elements or teeth,

called scoops, both rows of scoops passlngthru a slider which when moved in one direction guides the scoops into interlocked relation to close the fastener, and when moved in the opposite direction separates the teeth to open the fastener, and is concerned with improvements in the manufacture of such fasteners.

In the accompanying drawings:

Fig. 1 is a plan view of a complete fastener,

Fig. 2 is a perspective yiew, partly in section, of one form of apparatus for making fastener elements in accordance with my invention, the stripper plate being removed, for clearness,

Fig. 3 is a cross-section of the complete apparatus corresponding to the line 3-3 in Fig. 2 and including the stripper plate,

Fig. 4 is a perspective view of a fastener unit at one stage of the process of manufacture,

Fig. 5 is a perspective view of a hoppering or arranging machine,

Fig. 6 is a view partly in section of an assembling machine,

Fig. '7 is a plan view of the machine shown in Fig. 6.

Fig. 8 is an enlarged sectional view of a portion of the setting rollers and adjacent parts shown in Fig. 6, and

Fig. 9 is an enlarged cross section on the line 9-9 of Fig. 6.

Slide fasteners are well known and in common use, having a pair of supporting members or stringers, in the form of tapes l0, which are sewed to the edges of the article or garment to be closed or fastened, and which are provided along their adjacent edges with interlocking teeth or scoops II. The two rows of scoops are passed thru a slider I3, which when moved to the left as shown in Fig. 1, interlocks the scoops, and when moved toward the right separates the scoops to open the fastener. The tapes are usually secured together at the bottom of the rows of scoops by a bottom stop l4, and each tape is provided with a top stop I5, which top stops prevent the slider from accidentally coming off the rows of scoops when the fastener is closed.

Referring to Fig. 4, which shows a pair of scoops at one step in the process of manufacture, it is seen that each scoop includes a head portion having a projection 16 which fits into the recess H in the adjacent scoop when the fastener is closed, the head having a cam face I8 which facilitates the interlocking of the scoops. Each scoop also includes a forked attaching portion having a pair of forks or prongs which are clamped about the bead or cords 2| at the edge of the tape, and thus secure the scoop to the tape.

Fasteners as above described have been made on a large commercial scale in machines of the construction shown in my United States Patents 1,331,884 and 1,467,015. While these machines operate satisfactorily, the scoops produced by them may be somewhat rough due to burrs and sharp corners left by the dies in which the scoops are formed. To overcome this dimculty, it has been proposed to tumble the scoops in a tumbling barrel to smooth them before attaching them to the tape. This proposed step has two disadvantages. First it is dlflicult to arrange the scoops in an orderly fashion and attach them to the tape after they have once gotten out of a controlled orderly arrangement. This is due partly to their irregular shape, and partly to the fact that each scoop is about as long as it is wide, which increases the difliculty of arranging them, by automatic means, with their prongs pointing in the same direction, and their head projections 16 all facing in the same direction, both of which are necessary before they can be clamped to the tape. While automatic hoppering machines have been constructed for arranging scoops after tumbling, it has been found that. they are slow in operation.

One of the objects of my invention is to provide a process of making scoops by which they can be hoppered and arranged much more easily and rapidly than they have heretofore.

A second disadvantage of making scoops by the previously known methods and then tumbling them to smooth them is that in the tumbling operation the corners between the inner surfaces and the side surfaces of the prongs become rounded or the inside surfaces themselves of the forks or prongs become so smooth that they do not adhere to the tape satisfactorily.

Accordingly another object of this invention is to provide a method of tumbling or smoothing the scoops, or otherwise finishing them, in which the inside surfaces of the forks remain rough and unfinished, thus providing a very efiective clamping means for attachment to the tape.

Another disadvantage of the assembling machines shown in the patents referred to above is that the machines are complicated and expensive, partly because of the number of expensive reciprocating parts which must be opof illustration.)

erated at high speed and yet kept in accurate. adjustment and perfectly coordinated.

Accordingly, another object of the invention is to Simplify the forming of the fasteners and their attachment to the tapes, more specifically it is my object to form the scoops by simple punching operations, and attach them to the tape by a simple, economical rotating machine, free from reciprocating parts.

Other objects and advantages of the invention will be apparent from the accompanying description, drawings and claims.

One feature of the invention consists, essentially in forming the scoops in pairs, and keeping each pair together as a single unit, which is manipulated thruout a large part of my process. as'a single element, then separating the unit into individual scoops and attaching them individually to the tape.

Fig. 2 illustrates one form of apparatus for carrying out my improved method of forming scoops. A fiat strip of metal stock 25 is fed intermittently and automatically by any suitable means not shown, to a punch press having a stationary die member 26 and a head 21 which is reciprocated in the usual way in synchronism with the feed of the stock and is provided with a number of punches for carrying out the various punching or forming and cutting operations.

The first step consists in punching out a por-. tion of the stock into a blank having two headforming portions 28, by means of the cutting punches 29 and cutting die 30. Then as the head is raised, the strip 25 is automatically advanced one step, the blank 28 stopping over the forming die 32. At the next descent of the head 21, the forming punches 34, cooperating with the die 32 form the heads of the scoops, including the projections l6, recesses I1, and cam faces I 8. In this operation the edge surface 36 of the stock strip forms the cam face I8, the strip 25 being carefully cut to width for this purpose. (In Fig. 2 a portion of the die 32 is cut away for clarity The head is again raised, the scoop projections l6 are ejected from the forming dies 32 by means to be described, and the strip is advanced another step, stopping with the headed blank directly beneath the piercing punch 39 and over the die 40 (see Fig. 3). The next descent of the punch press head punches out a plug 4|, in die 40 and against an ejector 42 reciprocable in the die and urged upward by a spring 43. As the punch 39 recedes, the spring 48 forces the ejector up, replacing the plug 4| in the blank, where it fits tightly enough to force the blank up against the stripper plate 44, and this removes the heads Hi from the die 32. The stock strip is then advanced another step until the blank comes to rest over the cut oif die 46 and under the cut off punch 41. When the press comes down again the completed blank is cut off to produce the unit 48 shown in Fig. 4, a pair of complete scoops, held together by the interengagement of the prongs 20 and plug 4|. It is noted that the punch 41 completely severs the scoops at 49. I

The units 48 are next finished, by which I mean that their outer surfaces are smoothed,

for example by tumbling the units in a tumbling barrel in a mass of abrasive or finishing material. Such material may be the units themselves, steel balls, powdered emery, sawdust, or whatever material is suited to the scoop material and the degree of smoothness desired. Likewise in accordance with the invention, the units may be finished by painting, enameling, electro-plating, or in other ways, either in place of or in addition to tumbling. a

After being tumbled and suitably cleaned of the tumbling material, if necessary, the units are placed en masse in an automatic hopper 50 of known type, which delivers the units one at a time, properly oriented, into a chute 5|.

It will be noted that the completed individual scoop is of irregular triangular shape, and that its length is about equal to the width at the points of the prongs. This has heretofore presented difflculties in arranging the scoops in order by automatic machinery. It will be understood that before the scoops can be fed to a clamping machine they must not only be arranged with their prongs all pointing the same way, but mustalso have their head projections facing in the same direction. By holding two scoops together in the form shown in Fig. 4, a blank is provided whose length is greatly in excess of its width. Preferably the length exceeds the width by at least half. This shape has been found greatly to facilitate hoppering or arranging the blanks in automatic machines of known type, and simplifies the design of the hopper and increases the reliability of its operation.

The hopper 50 delivers the units 43 to the chute 5| with their long dimensions or major axes of symmetry in alignment. The units slide down the chute by gravity, the chute being vibrated if desired to make more certain the movement of the units. At the end of the chute 5| the units strike a stop 52 and slide sideways down a second chute 53, provided with suitable grooves 54 to receive 2..

the projections l6 and prevent the units from turning.

The lower end of the chute 53 is vertical, and terminates above a pair of notched wheels 55, whose notches 55a are of the proper shape and size to receive and retain the head of a scoop while permitting the prongs to extend beyond the periphery of the wheel. Guard plates 56 above and below the wheels keep the scoops from coming out of the notches vertically. The wheels 55 are rotated by any suitable means, not shown, and are synchronized and coordinated so that they both present a notch simultaneously in register with the slot in the chute 53. When this occurs, a unit 48 drops into the pair of notches,

one scoop being held by its head in each wheel. As rotation continues, the plug 4| is positively ejected by the stationary stop 51, and each separate scoop is carried by its wheel to the station.

where it is attached to a tape.

A tape I0 is fed close to the periphery of each of the wheels 55 at a point which may conveniently be diametrically opposite the chute 53. The tape is fed by any suitable means such as the rollers 6| at a linear speed equal to the peripheral speed of the wheels 55. The notches of the wheels are spaced at the intervals which the scoops are to occupy on the tapes. As the scoops approach the tape, the prongs surround the bead 2| at the edge of the tape, as shown best in Fig. 8, and at this time the prongs and tape pass between the clamping or setting rolls 62 and 63 which roll the prongs together and clamp the scoops securely tothe tape. After passing out of the grip of the setting rolls, the tape is elevated by the feed rolls 5| which are high enough to lift the scoops out of the notches in the wheels 55.

It has been observed that the plugs 4| remain in place between the prongs of the scoop units during the tumbling or finishing operation. In the blanking operation the punch 39 has removed the plug ll to form the prongs 20 by a shearing operation which leaves a sharp corner between the inner surfaces and side surfaces of the prongs thus formed, and also forms rough inner surfaces. When the plug 4| is replaced between the prongs by the ejector 42 it lies flush with the side surfaces'of the scoop blank and thus forms a protective member which prevents the tumbling material from rounding the comers of the prongs and also forms a. protective covering which prevents the finishing or smoothing of the inner surfaces of the prongs. After the plug has been removed by the stop 51 in the assembling operation the scoops are left with sharp corners and rough inner surfaces which grip the tape much more firmly than a smooth surface or a rounded corner.

It will be noticed that the scoops are formed by a series of simple punching operations not requiring expensive or complicated machines, and

i that they are assembled and secured to the tapes satisfactorily. Moreover the shape of the units has been found to facilitate the hoppering and arranging of the units to such an extent that the number of units delivered, properly oriented, by a single hopper to a chute is about three times the number of single scoops delivered in, the same length of time by machines heretofore known. And since in this case each unit provides two scoops, the speed of operation of a single machine is increased six times by my new process.

This arrangement can be used to apply scoops to tape in continuous lengths, or the scoops can be grouped on the tape in groups of desired lengths separated by an interval of free tape by the simple expedient of periodically interrupting the feed of scoops from the chute 53. This can be done by any suitable means, automatic or otherwise, not shown.

While I have described and illustrated one form of carrying out my invention, this is for the purpose of exemplification only, and it will be understood that my invention is not limited to the particular form shown, but includes other forms and methods embraced within the scope of the annexed claims.

I claim as my invention:

1. "The method of making a fastener element having a pronged attaching portion which consists in operating on a blank by forming the element including punching a body of material out of the blank to form the prongs, replacing the body between the prongs to cover their inner surfaces, finishing the exposed surface of the element and removing the body to leave unfinished inner surfaces on the prongs.

2. The method of making small articles which consists in removing a body of material from a blank to form the blank into the article, replacing the body in the position which it occupied before removal from the blank, and finishing the exposed surface of the article while retaining the body in position.

3. The method of making fastener elements each having a pronged attaching portion which consists in forming a blank for a pair of elements, removing a portion of the blank from between its ends to form a pair of pronged attaching portions secured to each other, replacing the removed portion to cover the inner surfaces of the prongs, cutting the blank to sever the attaching portions to form two individual elements while maintaining the elements and replaced portion of the blank in assembled relation, finishing the elements while so assembled, and subsequently separating the elements and removing the said blank portion to leave unfinished inner prong surfaces.

4. The method of making fastener elements each having a pronged attaching portion which consists in forming a blank for a pair of elements, removing a portion of the blank from between its ends to form a pair of pronged attaching portions secured to each other, replacing the removed portion to cover the inner surfaces of the prongs, finishing'the blank, and subsequently removing the portion to leave unfinished inner prong surfaces and separating the blank into two individual elements.

5. The method of making a fastener element having a pronged attaching portion which consists in forming the element, placing a member between the prongs which lies flush with the side surfaces of the prongs, finishing the exterior surface of the element while maintaining said member in position, and removing the member to leave prongs having sharp corners.

6. A twin assemblage of fastener elements having pronged base portions facingeach other and a separate member connecting said elements and covering the inner surfaces of said prongs, the outer surfaces of the fastener element being exposed, said member being adapted to be removed after finishing the outer surfaces to provide two individual elements with rough inner surfaces.

GIDEON SUNDBACK. 

